1. Field of the Invention
The present invention relates to a device for measuring a battery characteristic of a sealed battery and a measuring method for the same.
2. Description of the Related Art
Conventionally, in order to evaluate a battery characteristic such as an electromotive force of a battery or a discharging characteristic of the battery, the battery is discharged under a prescribed condition, and change in voltage between positive and negative electrodes per fixed time and the voltage between positive and negative electrodes per battery discharging capacity are measured and evaluated.
Moreover, when evaluating each single pole of positive and negative electrodes, the single polar condition is reproduced by using a simple cell and a reference electrode, etc., and by measuring the voltage of the cell, etc., the evaluation is conducted. (See, Akira Fujishima, Masuo Aizawa, and Toru Inoue, “Methods of Electrochemical Measurement”, Gihodo Publisher, Chapters 3 and 4, Experimental Chart 3.1, FIG. 3-2, and the like).
According to a method for measuring the voltage between positive and negative electrodes per fixed time, and the change in the voltage between positive and negative electrodes per battery discharging capacity for determining the battery characteristic, the battery voltage that appears as a phase difference between positive electrode potential and negative electrode potential is evaluated. Therefore, the problem is that it is difficult to determine whether the voltage thus obtained and the battery characteristic are caused by a positive electrode material or a negative electrode material, and it is difficult to obtain a useful information for a material development of the positive/negative electrode materials. For example, in the battery voltage of 1.5 V, there is a case that the positive electrode potential is 1.2 V and the negative electrode potential is −0.3 V, or there is also the case that the positive electrode potential is 0.3 V, and the negative electrode potential is −1.2 V.
Meanwhile, when evaluating the positive electrode material and the negative electrode material per every single pole using a simple cell and a reference electrode, etc., for example, the potential per every positive electrode and negative electrode and the battery characteristic can be measured by placing the reference electrode near the electrode intended to be measured. However, the evaluation results obtained by such a measuring method have various problems when the above evaluation results are applied to an actual battery such as a sealed alkaline-manganese battery, because the evaluation results are obtained from the measurement using a simple cell which is largely different from the actual battery in an electrode structure, a battery structure, and the like.
Therefore, the present invention provides the battery characteristic evaluation device and the battery characteristic evaluation method capable of separately and precisely measuring the potentials of the positive electrode material and the negative electrode material, without largely breaking the shape of the original battery shape of the sealed battery such as a sealed alkaline-manganese battery.